Still billing after cancellation

Vodacom sold two contracts with cellphone number *** & *** to me via the telephone. I called them back and cancelled the contracts because I did not want the contracts, they gave me a reference number(A1-XA4S-INA1VY) and said the will came and collect the devices and I should not open it, but they never cancelled the contracts or collect the devices. I am fed up, I have been struggling since last year July to sort this problem out. I want to cancel all my contracts